[en] Experiments on a compact plasma focus device (PFD) have been carried out in order to understand the accelerating mechanisms caused by the interaction of a supersonic plasma with an external magnetic field in a collisionless environment. The present study evaluates the effects of the inner electrode geometry of the PFD on the plasma flow and the resulting beam current. (author)

[en] Experiments with a plasma focus device (PFD) are being carried out for the understanding of the accelerating mechanisms in collisionless shocks, as a candidate for a new particle accelerating method for beam therapy applications. The current configuration operates under vacuum conditions (0.1 Pa) and is capable of achieving high plasma velocities above 40 km/s under different electrode configurations. A combination of two external tapered electrodes and two internal electrodes of conical tip, allowed us to evaluate the influence of the inter-electrode area in the accelerating performance of the PFD. The present study evaluates the effect of an external magnetic field on the plasma flow and the resulting beam current profile. (author)